How do I make a pulsating light effect material?
A pure-shader option, for use on a simple plane, or any surface:


The top branch wraps the circumference into segments, using a Gradient &gt; Radial node. The wrap is controlled by 'n Spokes' input.
The middle-ish branch wraps the radius into rings, by length from the object origin. The wrap is controlled by 'n Rings' input.
There are quite a few 'convenience' nodes in there, so the user doesn't have to fish around for tiny numbers, and to put 0 at the middle of each cell the plane is divided into, when the circumference-wrap and the radius-wrap are combined to give a per-cell X and Y.
The bottom branch splits the radius into color-bands, with an extra bit to dim the center to pure black, if you want to.

This sort of result:

I guess there's a limitation here.. the dots are not perfectly round. The 'Roundness' input fudges that. But they aren't round in your reference, either.
The effect is animated by keyframing the 'Phase' input.